Convertible athletic field

ABSTRACT

An athletic field having a synthetic turf surface is provided. The surface contains at least one opening in which is located a container filled with dirt or similar material packed to provide a surface substantially level with the base of the synthetic turf. These openings with the dirt filled containers provide an area on the synthetic turf covered field for sliding during sporting events in which sliding is required, for example, broad jumping, baseball, and the like. The openings and containers may be of various shapes, depending on the desired use.

United States Patent Kempson et al.

[ 1 Aug. 8, 1972 [54] CONVERTIBLE ATHLETIC FIELD [72] Inventors: George C. Kempson, Webster Groves, Mo. 63119; Arthur N. Gilbert, St. Louis, Mo. 63141 [52] US. Cl. ..273/25, 94/7, 273/55 R, 272/59 R [51] Int. Cl. ..A63b 71/00 [58] Field of Search....273/25, 55 R, 59 R; 272/59 R; 94/3, 4, 7; 161/36 [56] References Cited UNITED STATES PATENTS 3,323,802 6/1967 Riner ..94/7 X SYNTHETIC TURF TURF SUPPORT SURFACE 3,343,843 9/1967 Stanko ..94/7 X Primary ExaminerRichard C. Pinkham Assistant Examiner-Theatrice Brown Attorney--Russell E. Weinkauf, Neal E. Willis and John D. Upham [57] ABSTRACT An athletic field having a synthetic turf surface is provided. The surface contains at least one opening in which is located a container filled with dirt or similar material packed to provide a surface substantially level with the base of the synthetic turf. These openings with the dirt filled containers provide an area on the synthetic turf covered field for sliding during sporting events in which sliding is required, for example, broad jumping, baseball, and the like. The openings and containers may be of various shapes, depending on the desired use.

2 Claims, 1 Drawing Figure COMPRESSIBLE FOAM PAD ON TOP EDGE AND SIDES OF CONTAINER DIRT COMPOSITION CAVITY IN SUPPORT SU RFACE PATENTEDAU; 8 I972 COMPRESSIBLE FOAM PAD SYNTHETIC ON TOP EDGE AND SIDES TURF OF CONTAINER DIRT COMPOSITION TURF BASE CONTAINER CAVITY IN SUPPORT SURFACE SUPPORT SURFACE CONVERTIBLE ATmE'nc FIELD This invention relates to athletic fields covered with synthetic turf. More particularly, this invention relates to such fields which are provided with areas in which sliding on a dirt surface may occur.

Recently, synthetic turf has found rathersubstantial use due to innovations in the manufacture thereof. For example, the turf described in US. Pat. No. 3,332,828 is now employed in several large stadiums where it is used as a playing surface for various sports. In some of the places that synthetic turf has been installed, there are provided systems whereby the covered field may be converted, e.g., from a football or soccer field to a baseball field. Since baseball traditionally employs dirt base paths, this conversion requires that the synthetic turf be anchored around the paths and when the field is to be used for football, the dirt is taken up and/or covered with synthetic turf, usually on a rigid support. Such a system is costly since it requires the installation of several anchoring trenches. It would be desirable to provide an athletic field covered with synthetic turf which required anchoring trenches only at the periphery thereof and yet had features which enabled the athletes to slide on a dirt surface for sports such as baseball, broad jumping, and the like.

In accordance with this invention there is provided an athletic field covered with a synthetic turf surface, said surface having at least one opening therein in which is located a container filled with dirt, said dirt being packed so as to provide a dirt surface substantially level with the base of the synthetic turf surface and substantially level with the top of the container.

The container should be removable so that when it is desired to convert the field to, e.g., a football field, the container can be removed and replaced with a like shaped section of synthetic turf which will usually be attached to a rigid support. In order to insure that the container stays in place when in use, itis preferable that some type of means be provided for that purpose, for example, spring hooks or the like which are adapted to be connected with the base of the synthetic turf or to a connection located below the turf. The shaped section of synthetic turf used to replace the container should preferably have like connection means on the rigid support. Another method of securing the container is to make it slightly larger than the opening so that it fits snuggly therein. Also, compressible foam on the edges of the container aid in holding the container in place.

The shape of the opening and the container may vary depending on the particular athletic event which it is desired to accommodate. In broad jumping the opening and container will be rectangular. On the other hand, for baseball, since it is traditional in that sport for base runners to slide into the bases, the openings and containers would be L-shaped with the bases located at the angle of the L. This allows the runner to slide into, or back to any base. Since it is likewise traditional for the dirt area around home plate to be rather large, it can be supplied by a circular opening and container if desired.

As stated above, the shape of the opening and container or containers may vary for the reasons given. The depth of the container must be sufficient to allow an athlete to complete his slide on the dirt. A depth of about 3 inches has been found necessary for this purpose with about 6 inches being the preferred depth. The maximum depth is not critical except to the extent that it should not be so deep as to make removal difficult. A 10 inch deep container is considered the maximum practical dimension.

The container may be made of any convenient material which is capable of holding the dirt, such as metal or thick plastic. Of course, the lighter the container, the easier the interchange. Preferably small holes are made in the bottom to allow for water drainage.

The term dirt as used herein is intended to include natural soil as well as sand, clay and the like. The important thing being convenience to the athlete.

EXAMPLE An outdoor baseball stadium was covered completely with a synthetic turf surface except for .a ten foot wide area surrounding the outfield and which served as a warning track for outfielders pursuing fly balls. Also, an area about 3 feet wide adjacent to the stands was left uncovered to allow for construction of a trench to anchor the turf. The synthetic turf employed was of knitted construction and as described in US. Pat. No. 3,332,828. The turf was anchored into a trench dug around the periphery thereof and the trench was backfilled with dirt to even the surface.

A regulation baseball diamond was mapped out on the artificial turf surface. L-shaped openings were cut in the surface at the areas of first, second and third base in a manner such that the bases would be placed at the angle of the L and slightly to the inside. The openings were 20 feet long on the outside of both legs of the L and 16 feet long on the inside of both legs for the first and second base areas. Both legs were 6 feet wide. The third'base L was 24 feet long on both legs on the outside and 18 feet long on the inside.

The surface under the opening was excavated to a depth of about 6 inches. Containers having the dimensions of the openings were inserted into the excavated area. The containers were made of stainless steel and had openings in the bottom to allow for water drainage. The tops of the containers came to a height slightly below the base of the synthetic turf so as to be substantially level therewith. An energy absorbing foam pad was placed on the top of the container rims and over the outside to permit a snug fit. Sand and clay were placed in the containers and packed so that the dirt surface was level with the base of the synthetic turf.

Conversion of the baseball field was accomplished by removing the containers filled with dirt and replacing them with panels, having the dimensions of the openings, of synthetic turf mounted onto a rigid support which was designed to fill the openings and make the synthetic turf surface level with the permanent synthetic turf surface.

We claim:

1. A convertible athletic field comprising a support surface, a synthetic turf mounted on said support surface, said synthetic turf having a base being adjacent said support surface and blade elements connected to and extending upwardly from said base, said support surface and said synthetic turf having coextensive openings defining a cavity and a container having a bottom plate, sides extending upwardly from said bottom plate, an energy absorbing foam guard mounted on the said foam guard being a level extension of the base of top of said sides and extending over to the outside said synthetic turf.

thereof and a dirt composition filling Said container and 2. The convertible athletic field of claim 1 wherein being level with the upper portions of said foam guard; said container being removably inserted into said cavity 5 ig g gwg f g gg plate provlded openings with said energy absorbing foam guard fitting snugly against said synthetic turf, said dirt composition and 

1. A convertible athletic field comprising a support surface, a synthetic turf mounted on said support surface, said synthetic turf having a base being adjacent said support surface and blade elements connected to and extending upwardly from said base, said support surface and said synthetic turf having coextensive openings defining a cavity and a container having a bottom plate, sides extending upwardly from said bottom plate, an energy absorbing foam guarD mounted on the top of said sides and extending over to the outside thereof and a dirt composition filling said container and being level with the upper portions of said foam guard; said container being removably inserted into said cavity with said energy absorbing foam guard fitting snugly against said synthetic turf, said dirt composition and said foam guard being a level extension of the base of said synthetic turf.
 2. The convertible athletic field of claim 1 wherein said container bottom plate is provided with openings to allow for drainage. 